COMPUTER GAMES OF NOVELS

I was wondering if anyone could tell me more about how novels get turned into computer games. Like Tom Clancy's books for example which have now been turned into computer games, will his agent have gone to the game producers with the idea and if so why aren't other agents doing the same thing, or is more likely the producers sought him out. Does that mean he'll get royalties of every game sold?. It is mostly the case that the game comes out roughly the same time as the movie, e.g Lemony Snickets and Harry Potter. So is this two seperate deals, one for the movie production and one for the game production or is the game included in the merchandising rights which the movie studios pay the author

Computer game rights are subsidiary rights.

Depending on the contract, either the author kept 'em, or the publisher bought 'em.

As to the games: either the person with the rights approached a game company, or a game company thought "Gee! That would make a neat game!" and went looking for the person who had the rights.

If it was the publisher, then (usually) whatever the game maker paid for the rights, the author would take half and the publisher would take half. If it was the author, the author would get all of the licensing fee.

Whether the author will get a royalty on each game sold will depend on the deal that was made with the game company. Could be a flat fee, could be advance-and-royalties, could be straight royalties.

Game rights and movie rights different rights. Perhaps the movie studio bought game rights at the same time they bought movie rights, then they sold the game rights to some other company. Who knows these things without seeing the contract?

Any decent agent will try to sell as many rights as possible to as many places as possible. Any publisher who has a bunch of subrights will try to peddle them. The problem is that not every novel would make a good (as in, a lot of people would buy it) game.